Oh well, I finally bit the bullet, er, piston!

[Wrambler]

I haven't been over here in a while but I've kept a stroker in mind. Today my Evilbay search popped up these.

http://cgi.ebay.com/ebaymotors/ws/eBayI ... 0292049573

So being as they are coated skirt and carried a good price and free shipping with buy it now, I bit...
They are now mine, I hope!

Recipe is a very clean standard bore block I have been sitting on for quite some time.
1973 12 weight 4.2L crank, 60K on it nad it is perfect!
1972 4.2L rods, same motor also perfect! The bearings were mint when it came apart silver and scratch free the whole way around and across!

What I have to decide on now is
Rings? being the block will be honed and cleaned but not bored is there one particular ring that will work better than others?
Cam? That one is a tough one, do I want to stick to a stock stick? aftermarket? I got some thinking on this one... It's going in my 69 American, maybe?, 91 Allready running OBD I injection from a Wrangler.

The had is a standard favorite casting [forget the number] has been cleaned up and ported but no major stuff done. I may use this as time to get a professoinal three or more angle valve job done.

My other questions are since this will be a true lowbuck stroker build, should I deck the block 010-020" while it's down?
My twisted side is considering decking to zero the pistons and running it on E85.

I'll take any suggestions and comments on the build, no hurry at all. I was not intending to do this right now and process will be slow.
I did not want to pass up the pistons as standard bore pistons can be hard to get ahold of from time to time. Some guy tried to charge me $200 for standard bore 677ps last year! And they were used on 4.0L rods too!

Anyway, thanks for thoughts and tips, been a long time!
Mark

[Cheromaniac]

The H825CP's are good pistons (hypereutectic with graphite-coated skirts) and use standard non-metric 5/64", 5/64", 3/13" rings. They have a dish volume of about 15cc, a compression height of 1.592", and yield a 9.5:1 CR without decking the block/head. Deck clearance comes in at 0.038". If you shave 0.020" from the block deck, you'll need to increase the piston dish volume/combustion chamber volume by a combined total of 4cc to maintain the same CR. If you decide to go for zero deck clearance alone, the CR will be increased to 10.3:1.

[Mgardiner1]

The H825's are standard rings
The H802's are metric rings

Does one have an advantage over the other?

[Wrambler]

The H825's are standard rings
The H802's are metric rings

Does one have an advantage over the other?

IIRC, the metric ring pack was designed to decrease drag, but I doubt the theory is very valid. I always figured the real reason was to decrease wallet load of the buyer!

I'm trying to figure out which rings to go with...as far as brand and style.
Now that I got confirmation of the sale and a refund of the $15 for shipping that I had to pay to use the buy it now and get free shipping I'm getting an itch to attack this thing!
Problem is I have so many piles of stuff that needs doing...Still I could convince myself it's a good idea to build the shortblock now as all the parts assembled will take up less room! Yeah, that's a good story!
I've not been doing any heavy reading over here for a while. What's the current theory on cams and cam life? I'm wondering if I should stay with a stock cam or buy a cam, or have one of the two good stock cams I have reground to get the wider lobe surface the stock blanks have. Then I have to add pushrods and calculations for correct length into the mix.

[Mgardiner1]

LOL actually on summit racing, the metric combo in speed pro is cheaper then the standard

H802CP = $20.99 a piston * 6 = $125.94 + Metric ring set $85.99 = $211.93
H825CP = $29.99 a piston * 6 = $179.94 + Standard ring set $39.99 = $219.93

[Wrambler]

LOL actually on summit racing, the metric combo in speed pro is cheaper then the standard

H802CP = $20.99 a piston * 6 = $125.94 + Metric ring set $85.99 = $211.93
H825CP = $29.99 a piston * 6 = $179.94 + Standard ring set $39.99 = $219.93

works out for me though!
I paid $120 total for the H825CP and now I can buy the cheaper rings!
Seems strange they have a lower price on the metric ring pistons and a higher price on the rings!

[Mgardiner1]

yeah your not kidding! you know they gotta mold the slugs out of the same casting, and then whatever machine cuts the grooves just uses a different tool and just cuts them to a different spec.

What i'm getting at is, I'm sure they cost the company exactly the same amount to make them!

[gradon]

Yeah I noticed the $ dif too. Standard pistons more money than the metric ones and vice-versa for the rings--kinda silly, but does seem to fall in line with Jeep quirks.